A refinement of the Gribov-Zwanziger approach in the Landau gauge: infrared propagators in harmony with the lattice results

TL;DR

This paper refines the Gribov-Zwanziger framework to produce analytical infrared propagator results that align with recent lattice QCD data, addressing gauge copy effects and BRST symmetry breaking.

Contribution

It introduces a refined approach within the Gribov-Zwanziger framework that better matches lattice results for infrared propagators, including detailed analysis of BRST symmetry breaking.

Findings

Infrared gluon propagator is suppressed and nonvanishing at zero momentum.

Ghost propagator is not enhanced, consistent with lattice data.

The refined approach aligns analytical results with numerical simulations.

Abstract

Recent lattice data have reported an infrared suppressed, positivity violating gluon propagator which is nonvanishing at zero momentum and a ghost propagator which is no longer enhanced. This paper discusses how to obtain analytical results which are in qualitative agreement with these lattice data within the Gribov-Zwanziger framework. This framework allows one to take into account effects related to the existence of gauge copies, by restricting the domain of integration in the path integral to the Gribov region. We elaborate to great extent on a previous short paper by presenting additional results, also confirmed by the numerical simulations. A detailed discussion on the soft breaking of the BRST symmetry arising in the Gribov-Zwanziger approach is provided.